To investigate the symbiosis effects of mycorrhizal fungi, iron and zinc nano-fertilizers on qualitative and quantitative traits, biochemical characteristics and water use efficiency of mung bean crops under water stress conditions, a split-factorial experiment was conducted based on a randomized complete block design with three replications in the two regions of Mehran and Malekshahi in Ilam province of Iran in 2017. The main factor included irrigation regimes at three levels: no water stress (control), moderate water stress and high-water stress. Subfactors included nano-fertilizers at four levels (without fertilizer, zinc, iron and zinc+iron nano-fertilizer), and arbuscular mycorrhizal fungi (AMF) at two levels (not inoculated and inoculated) in subplots. The results showed that the effects of location, irrigation, mycorrhizal, nano-fertilizer and interactive effects of irrigation×nano-fertilizer showed a significant effect on number of pods per plant, biological yield, grain yield, and protein content. The results also showed that moderate and high-water stress reduced the 1000-seed-weight compared to control (non-stress) by 8.5 and 17.3%, respectively. Based on the results, the increasing nano-fertilizers increased chlorophyll a and chlorophyll b. With increasing drought stress, superoxide dismutase and catalase activity, proline and water use efficiency increased. The results showed that addition of mycorrhizal fungi as well as joint application of iron and zinc led to an increase in the measured traits in mung bean crops grown under water stress conditions. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Deutschland, ein Teil von Springer Nature.
